It has been a most upsetting day...
I was using my powerbook this morning left it open and running.. went out to take the car to the workshop.. when i came back the new temp maid cleaned up my room, and my powerbook lid was closed... opened it up.. blank screen, but machine was still running.. could hear the HDD and fan.. fine. since I had no unsaved work so I rebooted it. no startup chime, still no video. force power off by holding down power button. couldn't turn it back on. press hard reset button at the back. still cannot turn on.
so I open up the back cover... cleaned out dust around the fan, and the heatsinks under the keyboard... reassemble.. pray, turn on.. It come on. I thought maybe my OS screwed, so I booted from OS X system cd and did a clean install.. rebooted fine. i just downloaded the latest system update from 10.2 -> 10.2.6 (cd was 10.2).. when it was time to reboot... blank screen again after it shut down. Same as before, computer is on, but no disk activity, no video.
Sometimes, pressing the reset switch would work, but sometimes after I force it to shutdown, it won't start up again.. I don't know what is causing it to behave this way. After messing around a bit, removing the battery and putting it back, leaving it alone for a while, then it would start up again when I press the button.
I think this is beyond my abilities to fix.. Cos I've pretty much ruled out the OS and HDD problems. might be the logic board. Thank goodness I bought AppleCare (extended warranty). I'm now backing up my data in preparation to send it in to Apple Service..